I'm not so sure the alignment pins are "unobtanium". I think they are just common Taper Pins:
http://www.reidsupply.com/GrpResults.aspx?st=TAPER+PIN&pid=0&aitm=GLH-503&apid=0&bi= -John ============== > Another mystery solved! > > My (late) father-in-law spent most of his career at Varian-Eimac, mostly > working on TWTs, BWOs, and the occasional magnetron. In one batch of his > goodies, along with the H&S SMA torque wrench, was a little box with some > tapered metal pins! I've wondered what those were for, and now I know! > > He was very happy when his daughter brought home someone who knew what > vacuum tubes were, even if he did think that the RF work I did as a ham, > even the 144 and 440 MHz stuff, was still practically DC... > > Bob K6RTM > ------------------------------ > > Message: 2 > Date: Mon, 20 Sep 2010 08:19:25 +0000 > From: Kit Scally <[email protected]> > Subject: [time-nuts] WG mounting h/w (2) > To: "[email protected]" <[email protected]> > Message-ID: > <[email protected]> > Content-Type: text/plain; charset="us-ascii" > > > Hi, > > > Well, still not strictly, strictly true ! > In Ku & K band earth stations I've worked in, I've never seen shoulder > screws used, although the equipment used was mainnly from the USA. > Next to you precision adaptors, SMA torque wrenches etc in your personal > goodie box are sets of tapered pins, about 35-40mm long - that fit various > diameter WG mounting holes (the old metric vvs Imperial issue again). > > You insert a pair of pins on diagonal corners then add bog-standard SS > hardware to the opposite diagonals & tighten. The tapered pins are then > removed and replaced with another pair of screws/nuts. This ensures > absolute (?) internal WG slot alignment. There are a few variations on > this theme if you must have absolutely minimum RL within that section of > guide or if one guide face is threaded. Hex-headed bolts are usually used. > > That may explain why shouldered bolts are seldom seen. > > Tapered WG pins fall into the 99.9999% unobtainium class of materials. > > > Kit > VK2LL > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
